Electric switch



ELECTRIC SWITCH Original Filed May 9, 1929 Patented Apr. 21, 1936 iJtii'ED STATES PATENT OFFIQ mesne assignments,

to American Electrical Corporation of Massachusetts, Boston, Mass., a corporation of Massachusetts Original application May 9, 1929, Serial No.

Divided and this application January 12, 1934, Serial No. 706,388

3 Claims.

This application is a division of my coi-pending application Serial No. 361,682, filed May 9, 1929,

The invention relates to an electric switch, it being an object of the invention to provide a switch whereby a plurality of contact points may be successively connected, the switch structure being simple, inexpensive and eicient in operation.

For a more complete understanding of the invention, reference may be had to the description thereof which follows and to the illustration of certain embodiments thereof on the drawing, of which Figure 1 is a rear perspective View of a switch embodying the invention.

Figure 2 is a fragmentary section on the line 2 2 of Figure l.

Figure 3 is a perspective View of a portion of a key-operated switch embodying the invention.

Figure i is a perspective view of a sector plate to cooperate with the part shown in Figure 3.

Figure 5 is a fragmentary front elevation of a panel on which a key-operated switch is mounted.

Figure 6 is a sectional view on the line 6-6 of Figure 5.

The switch illustrated in Figures 1 and 2 consists essentially of a suitable base IB of insulating material in which is journaled a shaft I I. A sector-shaped plate I5 is mounted on the rear end of the shaft Il l as by a screw I6 so as to rotate with the shaft, the plate l5 being preferably spaced from the base I@ as by a washer I'I. The plate I5 is provided with an arcuate edge I8, the center of curvature of which is concentric with the shaft I i so that the curved edge I8 moves upon itself when the plate I5 is revolved about the shaft I I. Contact elements 22 are provided for engagement with the edge E8 of the plate I5. These contact elements may each be supported by a suitable post 2! secured to the base I0, any desired number of contact elements 25, for which there is room on the base, being employed. It is ordinarily desirable that the sector plate I5 be not greater than a semi-circle and that the contact elements 2@ be arranged in arcuate series about the shaft II as a center so as to occupy less than a semi-circle, so that the sector plate I5 can be out of contact with all of the elements 25 when in one position, and in contact with all of the elements 26 when in another position. It is evident that the sector plate l5 can be moved into additive contact with the several elements 25 in succession. Each element 2E) consists preferably of a hollow cylindrical member of resilient material such as copper or brass. The element may be out (Cl. 20G-8) from a tube of such metal or may be formed. indicated on the drawing, b v curling a strip of resilient metal so that the ends overlap as shown. Each such element may be attached to its post 2,5 as by a screw 22 or by any other equivalent means. The point of attachment of each element to its post is preferably on the side remote from the side I6, each element being so arranged as to project a movable portion into the path of movement of the edge I8 of the plate I5, so that, as the plate revolves about the axis of the shaft II, the edge portion thereof engages successively the several elements 20 and moves the engaged portions radially outward so that they ride on the edge I 8 and maintain resilient contact therewith. Since the edge I8 rubs against the side of each element 2t against the resilient pressure of the element, both the edge and the contact portions of the elements are kept so that a good electrical contact is maintained. Fo-r operation of the switch, a suitable finger knob 25 may be mounted on the forward end of the shaft I I, a spring Washer 26 being provided, if desired, to furnish a certain amount of frictional resistance to rotation of the shaft ll and plate I5 so that the plate will remain in any position to which it is turned. The screws 22 may be employed, if desired, as binding posts to con.- nect wires to the respective contact elements 22. The plate I5 may be either a bridging conductor to connect the several elements 25 together or it may be connected to a wire by the use of the .screw I6 as a binding post so that the wire connected to the plate I5 may be successively and additively connected to the wires leading to the several elements 20.

Figures 5 and 6 illustrate an embodiment of the invention Which is operable by a key. To this end a lock barrel 3@ is mounted on a base 3l which is preferably of insulating material. This orm of switch is especially desirable where the switch is mounted inside of a cabinet, which, as shown, may have a steel wall 32 to protect the contents from unauthorized access or tampering. The barrel 39 is provided with a suitable key slot 33 into which a key may be introduced for the purpose of revolving an arm 35 which carries a pin 36 eccentric with respect to the axis of rotation of the arm 35. Mounted on the base 3I are one or more posts 2I each of which carries a resilient contact element 2t in a manner hereinbefore described. A sector plate 45 is suitably supported on the base 3i as by an insulating element 4I carried by pillars 42 which are secured to the base 3|. A bolt or screw 3 projects loosely through an aperture 44 in the plate 49 so that the plate can rotate about an axis coincident with or parallel to the axis of the bolt. The bolt preferably rits snugly in the aperture 44 so that the rotation of the plate thereon is against a suitable amount of frictional resistance. The bolt 43 is arranged coaxially with the axis of rotation of the arm 35. The pin 35, as it revolves around the axis of rotation of the arm 35, is adapted to engage the radial portions of the sector plate 4D. If desired, suitable notches d5 may be provided in these radial edge portions to receive the pin 36. rIhe arc subtended by the plate 4D is preferably such that a complete revolution of the arm 35 about its axis will move the plate 4E) into contact with all of the contact elements 26 which are mounted on the base 3|, and a complete revolution of the arm 35 in the opposite direction will move the plate 40 out of contact with all of the elements 20. Since the plate 40 is a current-carrying part, it is preferably insulated from the steel Wall 32 of the cabinet by any suitable means such as a conventional insulating bushing 5l) or by making the pin 36 of insulating material.

It is evident that various modications and changes may be made in the embodiments herein illustrated and described without departing from the spirit or scope of the invention as dened in the following claims.

I claim:

l. An electric switch comprising a member having an arcuate edge, said member being rotatable about the circle center of the arc of said edge, a plurality of posts mounted in arcuate series about said center, a contact element carried by each said post to project into the path of said arcuate edge, each element comprising a hollow cylinder of resilient metal surrounding a post and attached thereto at a point thereon remote from said circle center.

2. An electric switch comprising a thin disk sector rotatable in its own plane about the circle center of the sector, a plurality of posts mounted in arcuate series about said center beyond the outer edge of said sector with their axes substantially parallel to the axis of rotation of said disk sector, and a deformable metal cylinder attached to each said post, each said cylinder being engageable by the outer edge cf said sector as it rotates about said center.

3. An electric switch comprising a member having an arcuate edge, said member being rotatable about the circle center of the arc of said edge, a plurality of posts mounted in arcuate series about said center, a contact element carried by each said post to project into the path of said arcuate edge, each said element comprising a strip of resilient metal bent into cylindrical form with overlapping end portions secured to one of said posts, and means operable to rotate said member.

WILLIAM K. MASON. 

